The Western Circulation Link project is a unique treetop timber boardwalk for visitors that connects two parts of Taronga Zoo. Visitors can now walk between the Chimpanzee and the Snow Leopard exhibits with new views of the Barbary Sheep and the Himalayan Tahrs on their rock mountain.
The steep site at Taronga can be challenging for some visitors and the boardwalk provides compliant accessible ramps for everyone including visitors with prams or people with lower mobility. The boardwalk gives access to a restored heritage pavilion with framed views to the Sydney Opera House and the Sydney Harbour Bridge.
The site was selected to provide greater visitor amenity through an ‘experience’ that captured the potential of the zoo’s natural beauty. Views to Sydney harbour have been reinstated and wildlife viewing has been improved.
Timber specified for this boardwalk was to be Spotted Gum or Ironbark. We chose the Queensland Royal Species which is a mix of Queensland Spotted Gum and Grey Ironbark. This was sourced from sustainable plantation forrests in Queensland in accordance with DERM Australian Forresty Standards AS4708 2007.
The structural element of the project included posts with bearer and joist construction to the main boardwalk with height above ground varying from .6 to 2.5m above ground with the boardwalk traversing down the sloping site and through the rear of the Himalayan Tahr exhibit along with a ramp walkway out over the Barbary Sheep exhibit. Both sections of the walkway over the animal exhibit incorporated containment fencing of steel mesh withing the timber post balustrade structure. Along with an elevated platform mounted on 200mm round poles above the main deck for the keepers to observe the Himalayan Tahr exhibit. The project also incorporates a 70x20 vertical boarding on areas of ramp that return on themselves in order to conceal the sub floor area.
Decking used was 90x 35mm with wedge shaped sides to allow any debries to fall through and also incorporated an anti cupping scallop out of the bottom.
All timber used in the construction of the boardwalk is sawn and sanded giving a rough sawn appearance without the risk of splinters to the public yet not creating any slip issues associated with dreased timber.
Some of the many challenges that presented this project were the elevated nature of the structure, the steepness of the base site and the close proximity to trees that required protecting and or redesign of footings to accomodate. Working in and around animals of different species poses its own set of challenges from not being able to undertake works on three side of the exhibit at once, to requiring keeper supervision to complete tasks inside the exhibits.